Package org.apache.commons.collections4.functors

Class OnePredicate<T>

java.lang.Object

org.apache.commons.collections4.functors.AbstractQuantifierPredicate<T>

org.apache.commons.collections4.functors.OnePredicate<T>

All Implemented Interfaces:

java.io.Serializable, PredicateDecorator<T>, Predicate<T>

public final class OnePredicate<T>
extends AbstractQuantifierPredicate<T>

Predicate implementation that returns true if only one of the predicates return true. If the array of predicates is empty, then this predicate returns false.

NOTE: In versions prior to 3.2 an array size of zero or one threw an exception.

Since:

3.0

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
OnePredicate(Predicate<? super T>... predicates)	Constructor that performs no validation.

Method Summary

Modifier and Type	Method	Description
boolean	evaluate(T object)	Evaluates the predicate returning true if only one decorated predicate returns true.
static <T> Predicate<T>	onePredicate(java.util.Collection<? extends Predicate<? super T>> predicates)	Factory to create the predicate.
static <T> Predicate<T>	onePredicate(Predicate<? super T>... predicates)	Factory to create the predicate.

Methods inherited from class org.apache.commons.collections4.functors.AbstractQuantifierPredicate

getPredicates

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

OnePredicate

public OnePredicate(Predicate<? super T>... predicates)

Constructor that performs no validation. Use onePredicate if you want that.

Parameters:

predicates - the predicates to check, not cloned, not null

Method Detail

onePredicate

public static <T> Predicate<T> onePredicate(Predicate<? super T>... predicates)

Factory to create the predicate.

If the array is size zero, the predicate always returns false. If the array is size one, then that predicate is returned.

Type Parameters:

T - the type that the predicate queries

Parameters:

predicates - the predicates to check, cloned, not null

Returns:

the any predicate

Throws:

java.lang.NullPointerException - if the predicates array is null

java.lang.NullPointerException - if any predicate in the array is null

onePredicate

public static <T> Predicate<T> onePredicate(java.util.Collection<? extends Predicate<? super T>> predicates)

Factory to create the predicate.

Type Parameters:

T - the type that the predicate queries

Parameters:

predicates - the predicates to check, cloned, not null

Returns:

the one predicate

Throws:

java.lang.NullPointerException - if the predicates array is null

java.lang.NullPointerException - if any predicate in the array is null

evaluate

public boolean evaluate(T object)

Evaluates the predicate returning true if only one decorated predicate returns true.

Parameters:

object - the input object

Returns:

true if only one decorated predicate returns true